cPanel dies frequently

Our cPanel server, hosted in a VPS, dies several times a day. Not the whole server, just the cPanel backend stuff (cPanel, WHM, and webmail). http and whatnot continue to run fine.

Anyway, we're exploring the possibility that it's related to running out of memory (we only get 128 MB of RAM in our VPS and run a small CounterStrike server there too), but this has been a pretty stable platform for months; I'm not sure why it'd suddenly have started dying several times a day.

/etc/init.d/cpanel restart will bring it back up and all, but it's getting REALLY annoying. Has anyone seen the same happening? Any idea what's up?